I've put bits and pieces of code I've written here for my reference.
Strifeboats is a little Battleship game I made one summer to see how Python and its simple game module, Pygame, work. It's not written very concisely, but it was fun!
test_multiplier and its combinatorial version are programs designed to test a computer's multiplier by computing numbers that should be equal unless there are bugs in the multiplier. The original version generates numbers to test by simply looping through numbers a million at a time, while the combinatorial version tries to generate numbers that actually test each bit of the multiplier. This wasa little side-project while I was volunteering at NIST.
XMLConverter.java, appropriately, converts XML files in an old unused format into a new format used by NIST's Test Case Authoring and Management Tool. It uses Java's XML libraries to do so.